In 2015, an outbreak of Zika virus (ZIKV) in Brazil resulted in more than 4,000 cases of microcephaly in newborns and the infection of 1.5 million people. Lee D et al, have developed a simple, user-friendly, and highly sensitive Zika virus (ZIKV) detection method by incorporating optimized reverse transcription loop-mediated isothermal amplification (RT-LAMP) and a lateral flow assay (LFA). Streptavidin-coated gold nanoparticles (AuNPs) were gathered in the conjugate pad and anti-digoxigenin and biotin were also affixed at the test line and control line, respectively(Figure1). After loading of digoxygenin and ZIKV amplified products, the biotin-labeled RT-LAMP products formed a complex with AuNPs via streptavidin-biotin interactions. The AuNP/RT-LAMP complexes were immobilized at the test line by interaction between digoxigenin and anti-digoxigenin, whereas the AuNPs that did not form complexes were captured by biotin.
After 30 min of RT-LAMP reaction, the resultant ZIKV amplicons were simply and rapidly analyzed by the LFA test in less than 5 min. The korean researchers announced a high level of sensitivity down to a single ZIKV RNA copy/test in human whole blood that was previously spiked with extracted ZIKV RNA. The sensitivity and the specificity of their method need to be confirmed by testing clinical samples from ZIKV(+) patients and by comparing the LFA method with a reference real time PCR assay.